Why We Don't Need a 'Category 6' Hurricane Classification

With Hurricane Michael only hours away from making landfall, and with reports predicting it will likely be the most powerful storm to hit the Florida Panhandle since record keeping began in 1851, it seemed appropriate to tackle something that I’ve seen more and more during the past few hurricane seasons – reports about the dreaded “Category 6 storm.”

The simple logic is this: these storms are getting worse, and since most people have at least a vague familiarity with the 1-5 categorization scale for hurricanes, we need something bigger and bolder to convey that reality to the public. Because 6 is indeed a bigger number than 5, some seem to believe this will do the trick. It will drive the extra special seriousness of the situation home in a way that only large numbers can, which is incidentally why the DEFCON system probably confuses the hell out of so many people.

Okay, that was a bit flippant, let’s have another crack at that.

The slightly more complicated logic is this: we are seeing unprecedented wind speeds, storm surges and rainfall from hurricanes season after season and they are leaving behind correspondingly severe damage as a result. Since we have good reason to believe that the intensity of these storms can be directly linked to climate change, we may need to reflect that in the way that we categorize hurricanes, and the way we ‘sell’ them to the public, if you will.

Alright – I think we can both agree that’s less of a straw man argument.

My real problem with this Category 6 thing is two-fold:

1. I think it’s mostly utilized as a tool for selling fear.

2. It’s unnecessary due to the purpose of the scale itself.

To the first point, I think it’s obvious to many of us why news media employs hyperbole in this way. It gets attention. I have nothing wrong with that fact in principle, it’s just that I feel you can make the more serious argument about why this hurricane might be unprecedented without conjuring a 2012-esque disaster porn scenario starring John Cusack or Dennis Quaid. It turns people off, and I think it actually has the opposite of its intended effect on already climate change skeptical people. Politicians are among the worst offenders when it comes to this “Category 6” stuff, and that’s a problem in my opinion.

In order to understand the second point, you have to dig into what we’re actually talking about when we categorize hurricanes. The Saffir-Simpson hurricane wind scale (SSHWS) measures, as the name implies, wind speeds – more accurately maximum sustained winds of a minute or more. Oh yeah, it also only applies to storms in the western hemisphere, specifically ones forming in the Atlantic Ocean and northern Pacific Ocean east of the International Date Line. So yeah, cyclones and typhoons are categorized differently.

Technically, a Category 5 hurricane on the Saffir-Simpson scale is already classified as anything above 157 mph, so right there you don’t technically need anything above that threshold.

But don’t take my word for it. Robert Simpson (as in Saffir-Simpson) said himself that there was no need for a Category 6 on the scale because fundamentally the scale was designed to measure the potential damage a hurricane would have on human-made structures. Simpson stated that "... when you get up into winds in excess of 155 mph (249 km/h) you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it’s going to cause rupturing damages that are serious no matter how well it's engineered."

In other words, the storms may have changed, but the buildings haven’t.

Now there are legitimate criticisms to be made about the Saffir-Simpson scale, namely that it doesn’t take into account the physical size of a storm or the precipitation that it produces. There are also a number of proposed replacements to the Saffir-Simpson scale that seem relatively worthwhile of consideration, including the Hurricane Intensity Index and the Hurricane Hazard Index, which take a far greater number of variables into account.

Now all of that isn’t to say that I don’t think climate change is an incredibly important issue and that the frequency and damage of these hurricanes isn’t super alarming – it is, and they are. However, numbering hurricanes like we do iPhones is unlikely to be a significant motivating force in getting people to take this shit seriously.

So go ahead and change the way that we talk about and categorize hurricanes, I’m all for that. I just don’t like this Category 6 business – if we embrace it I see a “Hurricane XS Max” in our future. 

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